A potnetiometer is a three terminal resistor. Two terminals are across a fixed resistance, while the third is an adjustable connection anywhere along this fixed resistance. When you turn a knob on a pice of equipment, chances are you are turning a potnetiometer.

It is connected in a circuit like an adjustable voltage divider. Alternatively it can be used as an adjustable gain resistor in an opamp feedback.

Hoffmayer,
you have little to be joking about, thespeakerguy was sincerely trying to be helpful. Personally, I think this website needs to crank-up it's level a couple of notches. A multiple choice admission questionnaire is in order in my opinion. If you don't know what a potentiometer is you probably shouldn't be building any audio stuff, if you think that is ok to shorten the output of your zen amp at startup in order to prevent transient noise you probably should not be building any audio stuff, either. That is for your safety and the safety of your loved ones, too.
It seems that some people are expecting to be spoon-fed the knowledge they need by asking the stupidest questions rather than trying to open a book and teach themself something.